bindings/thermal/thermal-zones.yaml

1 # SPDX-License-Identifier: (GPL-2.0)
4 ---
5 $id: http://devicetree.org/schemas/thermal/thermal-zones.yaml#
6 $schema: http://devicetree.org/meta-schemas/base.yaml#
11   - Amit Kucheria <amitk@kernel.org>
20    - thermal-sensor: device that measures temperature, has SoC-specific bindings
21    - cooling-device: device used to dissipate heat either passively or actively
22    - thermal-zones: a container of the following node types used to describe all
25   This binding describes the thermal-zones.
27   The polling-delay properties of a thermal-zone are bound to the maximum dT/dt
29     1. when passive cooling is activated (polling-delay-passive)
30     2. when the zone just needs to be monitored (polling-delay) or when
36   unexpectedly between polls. Choosing the right polling delays shall avoid
42     const: thermal-zones
44       A /thermal-zones node is required in order to use the thermal framework to
48       platform-data regarding temperature thresholds and the mitigation actions
52   # Node name is limited in size due to Linux kernel requirements - 19
55   "^[a-zA-Z][a-zA-Z0-9\\-]{1,10}-thermal$":
60       this zone, one sub-node containing the various trip points for this
61       zone and one sub-node containing all the zone cooling-maps.
64       polling-delay:
68           checking this thermal zone. Setting this to 0 disables the polling
72       polling-delay-passive:
76           checking this thermal zone while doing passive cooling. Setting
77           this to 0 disables the polling timers setup by the thermal
81       thermal-sensors:
82         $ref: /schemas/types.yaml#/definitions/phandle-array
89         $ref: /schemas/types.yaml#/definitions/uint32-array
95             z = c0 * x0 + c1 * x1 + ... + c(n-1) * x(n-1) + cn
102       sustainable-power:
107           sustainable power of a 4-inch phone is typically 2000mW, while on a
108           10-inch tablet is around 4500mW.
115           be taken are defined in another node called cooling-maps.
118           "^[a-zA-Z][a-zA-Z0-9\\-_]{0,63}$":
124                 minimum: -273000
136                   (trip temperature - hysteresis). This potentially prevents a
143                   - active   # enable active cooling e.g. fans
144                   - passive  # enable passive cooling e.g. throttling cpu
145                   - hot      # send notification to driver
146                   - critical # send notification to driver, trigger shutdown
148                   There are four valid trip types: active, passive, hot,
161                   The passive trip type can be used to slow down HW e.g. run
168               - temperature
169               - hysteresis
170               - type
175       cooling-maps:
185           "^map[-a-zA-Z0-9]*$":
194               cooling-device:
195                 $ref: /schemas/types.yaml#/definitions/phandle-array
199                   device. Using the THERMAL_NO_LIMIT (-1UL) constant in the
200                   cooling-device phandle limit specifier lets the framework
213               - trip
214               - cooling-device
218       - polling-delay
219       - polling-delay-passive
220       - thermal-sensors
221       - trips
228   - |
229     #include <dt-bindings/interrupt-controller/arm-gic.h>
230     #include <dt-bindings/thermal/thermal.h>
234             #address-cells = <2>;
235             #size-cells = <2>;
239             tsens0: thermal-sensor@c263000 {
240                     compatible = "qcom,sdm845-tsens", "qcom,tsens-v2";
246                     interrupt-names = "uplow", "critical";
247                     #thermal-sensor-cells = <1>;
250             tsens1: thermal-sensor@c265000 {
251                     compatible = "qcom,sdm845-tsens", "qcom,tsens-v2";
257                     interrupt-names = "uplow", "critical";
258                     #thermal-sensor-cells = <1>;
264     thermal-zones {
265             cpu0-thermal {
266                     polling-delay-passive = <250>;
267                     polling-delay = <1000>;
269                     thermal-sensors = <&tsens0 1>;
272                             cpu0_alert0: trip-point0 {
275                                     type = "passive";
278                             cpu0_alert1: trip-point1 {
281                                     type = "passive";
291                     cooling-maps {
295                                     cooling-device = <&CPU0 3 3>, <&CPU1 3 3>,
302                                     cooling-device = <&CPU0 5 5>, <&CPU1 5 5>,
310             cluster0-thermal {
311                     polling-delay-passive = <250>;
312                     polling-delay = <1000>;
314                     thermal-sensors = <&tsens0 5>;
317                             cluster0_alert0: trip-point0 {
332             gpu-top-thermal {
333                     polling-delay-passive = <250>;
334                     polling-delay = <1000>;
336                     thermal-sensors = <&tsens0 11>;
339                             gpu1_alert0: trip-point0 {